Compounds capable of absorbing and/or emitting light can be ideally suited for use in a wide variety of optical and electro-optical devices, including, for example, photo-absorbing devices such as solar- and photo-sensitive devices, organic light emitting diodes (OLEDs), photo-emitting devices, or devices capable of both photo-absorption and emission and as markers for bio-applications.
FIG. 1 depicts an example of an OLED. As shown in FIG. 1, OLED 100 may include a layer of indium tin oxide (ITO) as an anode 102, a layer of hole-transporting materials (HTL) 104, a layer of emissive materials (EML) 106 including emitter(s) and host(s), a layer of electron-transporting materials (ETL) 108, and a metal cathode layer 110 on substrate 112. The emission color of OLED 100 may be determined by the emission energy (optical energy gap) of the emitter(s) in the layer of emissive materials.
Much research has been devoted to the discovery and optimization of organic and organometallic materials for using in optical and electro-optical devices such as OLEDs. Generally, research in this area aims to accomplish a number of goals, including improvements in absorption and emission efficiency, as well as improvements in processing ability. Despite significant advances in research devoted to optical and electro-optical materials, many currently available materials exhibit a number of disadvantages, including poor processing ability, inefficient emission or absorption, and less than ideal stability, among others. Thus, a need exists for new materials which exhibit improved performance in optical emitting and absorbing applications.